Fix a bug in type propagation.
If a phi requests its inputs to be of a certain type, the inputs need
to propagate that type to their users, as those users might be
phis.
Bug report and test courtesy of Serguei I Katkov.
Change-Id: I79baac271566ec4fa684c1edf11a1b3383d896a9

@@ -0,0 +1,3 @@
+Regression test for optimizing's type propagation:+If a phi requests its inputs to be of a certain type, the inputs need+to propagate that type to their users, as those users might be phis.